Find ddx[cos(x)ex]\frac{d}{dx}\left[\frac{\cos(x)}{e^x}\right]dxd[excos(x)].
−sin(x)+cos(x)ex-\frac{\sin(x) + \cos(x)}{e^x}−exsin(x)+cos(x)
−sin(x)−cos(x)ex\frac{-\sin(x) - \cos(x)}{e^x}ex−sin(x)−cos(x)
sin(x)−cos(x)ex\frac{\sin(x) - \cos(x)}{e^x}exsin(x)−cos(x)
−sin(x)ex-\frac{\sin(x)}{e^x}−exsin(x)